1. Field of the Invention
The present invention relates to a disk device an external memory device of a computer, and more specifically to disk cleaning.
2. Description of the Prior Art
Referring to FIGS. 8 through 11, there are illustrated operations of a magnetic disk and a magnetic head in a magnetic disk device, respectively. In each figure, designated at 1 is a magnetic disk, 2 is a slider for holding a transducer that is to record/regenerate information on/from the disk 1, 3 is a support spring for forcing the slider 2 to follow the disk 1, 4 is a tapered portion provided on the slider 2, 5 is an arrow indicating the direction of rotation of the disk 1 at recording and regeneration on the disk, 6 is an arrow indicating the direction of seeking by the slider 2, 7 is dust, and 8 is a non-recording region on the disk 1.
Operation of the above arrangement is as follows:
as illustrated in FIG. 8, the slider 2 is pushed against the disk 1 by the support spring 3 at a static state, and is allowed to make static contact with the disk 1.
Once the disk 1 starts to rotate in a direction indicated by the arrow 5, an air stream is produced on the surface of the disk 1 and is allowed to strike the tapered portion 4 as a wind pressure, which portion is thereby pushed up to float the slider 2.
The slider 2 is allowed to float and stop generally in a non-recorded region 8 of the disk 1 as indicated by a dotted line in FIG. 9. As the disk 1 goes into steady rotation, the slider 2 moves to a position indicated by a solid line 2 in the figure, and selects a track arranged coaxially on the disk 1 while seeking those tracks in the direction indicated by the arrow 6, to record/regenerate information on/from the track.
For the lifted attitude of the slider 2, the slider 2, which is pushed up and lifted by wind pressure exerted on the tapered portion 4 as shown in FIG. 10, is lifted to a higher position on the leading edge side where the tapered portion 4 has been provided, while being lifted to a lowest position, a height h.sub.2, on the trailing edge side.
Additionally, as illustrated in FIG. 10, any dust such as dirt (hereinafter referred to dust) existent around the disk 1 is entrained by the air flow with the rotation of the disk 1 to strike the tapered portion 4 of the slider 2 together with the air flow, and allowed to adhere partly to the tapered portion 4. This causes such dust to be accumulated on the tapered portion 4 located on the back side of the slider 2 for a long period of time, as illustrated in FIG. 11.
In the prior magnetic disk device, any dust is accumulated on the tapered portion with the elapse of time as described above. The slider is however difficult to be cleaned. Particularly, in a closed magnetic device capable of dealing with a recent trend of making the device high density, it is impossible to clean the interior of the device without disassembly the device, and accumulated dust interrupts the operation of the tapered portion to cause the unstable lifted attitude of the slider and hence head crashing.
To solve such a difficulty, there is known as a prior art "a magnetic disk device" disclosed in the device of Japanese Utility Hodel Laid-Open No. 62-57999. In this prior art, any dust adhering to a disk surface is scattered by a slider by rotating the disk at a low rotational speed in the same direction as the direction of rotation of the disk during recording and regeneration, and bringing the slider near to the disk surface to repeatedly seek the disk several times.
Accordingly, also in the prior device, although cleaning of the disk surface is likely to some extent, the dust will be still accumulated on the tapered portion, so that removal of any dust accumulated on the tapered portion is difficult, causing a malfunction of the tapered portion. Thus, there is still a problem that head crashings may occur.